Ultra high frequency signaltranslating apparatus



-FREQUENCY SIGNAL-TRANSLATING APPARATUS I J y2 1946- R. B. LAWRANCEULTRA-HIGH -Fileci 00. 29. 1941 2 Sheets-Sheet 1 INVENTOR IGHARD B. LAWRCE ATTOR NY July 23, 1946.

R. B. LAWRANCE ULTRA-HIGH-FREQUENCY SIGNAL-TRANSLATING APPARATUS FiledOct. 29, 1941 .2 Sheets-Sheet 2 INVENTOR RICHARD B. LAWRANCE AT'rohNEYPatented July 23, 1946 UNITED STATES PATEN T OFFICE ULTRA HIGH FREQUENCYSIGNAL TRANSLATING APPARATUS Application October 29, 1941, Serial No;416,986

The present invention relates to ultra-highfrequency signal-translatingapparatus and, particularly, to such apparatus of the type adapted to betuned over a wide range of operating frequencies.

Certain ultra-high-frequency signal-translating apparatus of the priorart has included a pair of parallel stationary conductors arranged as atwo-wire transmission line and tunable over a range of operatingfrequencies by a short-circuiting bar slidable along the conductors. Thearrangernent thus provided is effectively a twoterminalresonant circuitand has generally been used as a single-tuned stage between tandemstages of amplification or as a single-tuned stage of anloscillator. Inthe prior art arrangements of this nature, the coupling of anysignal-translating channels or associated vacuum tubes with the two-wiretransmission line has been accomplishedby coupling such channel or tubesdirectly or capacitively with the openend of the line, or anintermediate tap. It would be desirable, however, to couple to thetwo-wire transmission line by the use of an inductivecouplingarrangement which has the advantage that it can be arranged to, avoidground return currents. Such inductive coupling systems, however,must'be positioned in the vicinity of the shorting bar since this is theregion of maximummagnetic field intensity'and flux density about theconductors. Inductive coupling arrangements of this nature haveheretofore been used onl where the signal-translating apparatus isdesigned to operate at or near one frequency. No attempt has been madeto use such coupling arrangements where the apparatus is designed tooperate over a wide range of frequencies since the region of maximummagnetic field intensity about the conductors would move with theshort-circuiting tuning bar.

It is an object of the present invention, therefore, to provide a newand improved ultra-highfrequency signal-translating apparatus whichavoids one or more of the disadvantages and limitations of the prior artarrangements of this nature.

It is a further object of the invention to provide anultra-high-frequency signal-translating apparatus of the type includinga tuned transmission line and in which the region of maximum magneticfield intensity of the tuned transmission line remains stationary at apredetermined fixed location over a Wide range of tuning frequencies.whereby the transferof signal energy to and from the apparatus by afixed inductive coupling system remains maximum throughout the wide14Claims. (Cl. 25036) 7 high-frequency signal-translating A 2 a range offrequencies over which the apparatus is adapted toioperate. H

In accordance with the invention, an ultraapparatus comprises anelongated rigidconductor an s fixed conductive member slidablysupporting the conductor .and providing an electrical ground connectionthereto. There is provided mean's'including the conductor for forming aresonant circuit tunable'over a'range of frequencies by adjustment ofthe length of the conductor extending from one side of the aforesaidmember; The apparatus includes-means movable in unison with theconductor for supporting vacuum-tube apparatus and associated circuitelements at the end of the conductor on the aforesaid one side.

of the member. The apparatus also includes means for moving theconductor through the member to' tune'the resonant circuit to a predetermined operating frequency in the aforesaid frequencyrange. '31 I Inaccordance with a preferred form of the invention, a: signal translatingapparatus ofgthe type described comprisesa pair of elongated rigidconductors and a fixed member slidably'jsupport ing the conductors inparallel spaced relation and providing an electrical connection therebe-y tween, the conductors forming a resonant circuit tunable over arangeof frequencies by adjustment of the lengths of the conductors extendingfrom one side of the member, The region of maximum field intensity aboutthe conductors remains s'tation'ar'y'in the vicinity of the one side ofthe member over' the aforesaid range 'of frequencies. The apparatus alsoincludes means for moving the conductors in unison through the member.

to tune the resonant circuit to a predetermined, operating frequency inthe aforesaid frequency range. V

In accordance with a particular form of the invention, the apparatus ofthetype described includes means movable in unison with the cone. ductorfor supporting vacuum-tube apparatus. and associated circuit elements atthe end ofthe conductoron the aforesaid one side ofthe supportingmember. The apparatus may also in-- clude an elongatedmetallic-housingin which case the supporting member takes the form of :a partition wallfixedly supported transversely within the housing to divide the interiorthereof into two chambers, the partition wall having an aperturethroughwhich the'conductor extends. Means is providedfor supporting? theconductor in the aperture and for completing an electrical.ultra-high-frequency signal-translating appa ratus embodying theinvention; Fig. ssectional view of the Fig. 1 arrangement t i; along theplane 2'2; Fig. 3 is a perspective d tail view of an arrangement-forsupporting vacuum-tube apparatus and associated ments on one end of theparallel movab'l" conductors of the Fig. 1 embodiment gf-the invention;Fig. 4 is a cross-sectional view of a rn d fied construction ofultra-high-frequentysignaltranslating apparatus embodying the invention;Fig. 5' represents a complete ultra-high-frequency signal-translatingapparatus embodying the'invention in a modified form; *and FigrG'is acrosssectional view of the Fig. 5-arrangement taken aloh the plane 6- 6.

Referring more particularly to Fig. .1, there is represented a;cqmplete" ultra-high-frequency signal-translating apparatus embodyingthe present invention in the form of an ultra' higlf frequencyoscillator. The oscillatorincludesan elongated metallic housing In witha "conductive member or partition" wall I I fixedly supportedtransversely within the housing III to divide the interior thereof intotwo chambers I2 and I3: The partition -wall II has a plurality'of'apertures I4, 15, I 6"through which extend" a-plurality of elongatedrigid tubular conductors II, I8;'and I9, respectively. The apparatusincludes means for supporting-the conductors" Hf, I8, and I9 in parallelspaced relation and for completing a conductive connectiontherebetweenat a fixed point near the partition wall 'I I. comprising" aplurality of longitudinally-slotted sleeves 29:20 fixedly secured to thepartition wall 'I I in registry with individual ones'of the apertures14, I5; I6. The; partition wall 'II and sleeves ZII'thuscQm-i prise aunitary fixed member'slidably supporting individual ones of theconductorsll; lBfand I8 and provid flgan electrical connectiontherebetween and to; the casing Ill, usually-at'ground potential, at a fixedlocation near 'the' partition wall. The conductors "I1; and I9. as thusarranged and supported form a resonant circuit balanced to ground, Thisresonant circiut may, 'in one View of, the matter, be consideredtworesonant circuits each unbalanced. to ground'and'simul taneouslytuned by -movement-of the conductors I1 and I9 through the'partit ionwall II. This type of resonant circuit is comparable to that formed byan inductor having two equal-valued series condensers connected acrossits terminals,- ground connections being made to the center pointfof theinductorfand the junction of the condensers. resonant circuit is tunableover-a range of frequencies in accordance with the lengths; of the 'c ond ctors extending from that side of the partitl qmwall IfI which closesthe chamber IZ. The central conductor I8 is neut al." M I m IVacuum-tube apparatus comprising vacuum tubes 2| and 22 andhssociatedcircuit elements are supporte'djin a'manfie'rpresently' to beconsideredin" greater "detailf'on th'ose "ends of the conductors |-1;-I8: andj19which2te1id into the 75 4 chamber I2 and thus are movable inunison with the conductors. The cathodes of vacuum tubes 2| and 22 areenergized through respective pairs of radio-frequency choke coils 23, 24from an energizing circuit 25 which extends through the tubularconductor I8 but is insulated therefrom. By-pass condensers 2'6, 26connected between the"6ircuit' z's-afid nearer conductor I 8 maintaintheenergizing circuit 25"at' ground potential for currents of ultra-highfrequency. The

' grid of tube 2i is coupled through a condenser 21 to an optimum pointnear the end of cond tor]? andi's connected to the cathode-energizin gcircuit 25 through a grid-leak resistor 28 and a conductor 29 "whichextends through, but is ihsul'atedffrbrrij tubular conductor I9. Thegrid"oftube'z2is'similarly coupled through a condenser 30, team "optimumpoint near the end I of cpnductor I"! and is connected to thecathodeenergizing circuit 25 through a grid-leak resistor 3! and aconductor 32 which extends through, but "is insulated "from," thetubularc'di i'd1 ic tor 1, The anodes of tubes '2 I "and 22"aredirectlybonf nected to'the ends'of 'therespective"conductors and; V

The energizing circuit 25 emerges from the into chamber I3. The'grid-cir'cuitconductor2Q likewise emerges fromth'e tubular conductorI,9 in the chamber IS'and'is" connected to one side of the energizingcircuit 25" through a radiofrequency filter'homprising 'a seriesresistor 3.5

and shunt condenser Y36 and through a micream meter 31. Theother"grid-circuitconductor 3 2 similarly emerges into 'the c'hk'am berI3 and is connected'to"the"saine'side of the energizing cirfcuit 25through a similar" radiofrequency filter comprising 'a's'eriesre's'is'tor"3'3' and shunt con denser 39 and through a' microammeter40,1 The ends r thje'conductors11,1 8, therewit x; tend into the chamberI3 are mechanically and electrically connected "together by a conductiveyokej 41fAsource" of space-turr s such as a battery 42, isconnectedbtween thec'athodeenergizing circuit'25 and the yoke wherebyspace'current is suppliedto'tubes2I'and 22 die re'ctly through thers'pectivetubular conductors I a The batteries 34 and 42 may be supportedto move'withth'e yoke though in practice these batteries are preferablyfixedly positioned in the metallic 'hoii'sing I used are:electrically-connected to the e'n'ergizingcircuit "25 and the yoke 4lthrough "flexible 'conductors'. Alternatively, the, batteries Stand 42may be positionedexternally of thehousing It andjia either event; thebat;

- teri'es may be replacedby any' of the well-known I forms of cathodeand anode supply systems;

The oscillator is provided with an output circuit including a l'oopor'winding '45 dispOSedin the region r m ximum ma netic. field intensitydeveloped about the conductor I 9 in the vicinity ofth'e"pa'rtition'wal1 II "an th side, thereof.

which closes'the mg 45 rents a component or thefmutual inductan'ce typeof piston attenuator includingan opene'nded metallic cylindrical member43 fixedly sechamber I2. Theloop or windwall II over the range ofoperating frequencies.

of the oscillator. The loop winding 45 is coupled to a pair of outputterminals 46, 41 and there is connected across these terminals acenter-tapped impedance 48. A third output terminal 49 is connectedtothe center tap of the impedance 48 to provide a. balanced output circuitfor the oscillator. The inductance piston attenuator comprisin thecylinder 43 and loop or winding 45 is described in detail in a paper byDaniel E. Harriett and Nelson P. Case entitled The design and testing ofmultirange receivers, whichappears in the'Proce'edings of the Instituteof Radio Engineers, June, 1935, pages 578-593, inclusive.

In order to preserve substantial symmetry and electricalbalance oi thetuned circuit formed by the conductors I1 and I9, a dummy attenuatorcylinder Ellis securdin an aperture 5| provided in thewall of thehousing I0 at a pointdiametrically opposite the cylinder 43. Thecylinder 50 is closed at its outer end 52. s

Movement of the tubular conductors I1, I8, and I9 in uniSOn through thepartition wall II is effected by a rack 53 provided on the centerconductor IB, the rack 53 being driven by a pinion gear 54 which isfixedly secured to one end of a shaft 55. The other end of the shaft 55extends outside of the housin I 0 and has secured thereon asuitablecalibrated dialand operating knob 56. A dummy rack 51 is provided on thecenter conductor 'I8 diametrically opposite the rack 53 to preservesymmetry and electrical balance.

Considering now the operation of the oscillator arrangement justdescribed, vacuum tubes 2| and 22, connected in push-pull to theresonant circuit comprising conductors I1 and I9, generateultrahigh-frequency signal oscillations which develop standing waves ofpotential and current on the conductors I1'arid I9, the potential waveshaving a maximum value near'the ends of the conductors I1, I9 and thecurrent waves having a maximum value in the vicinity of the partitionwall II. Sustained oscillations are maintained by feeding back to thegrids of tubes 2| and 22 through the respective condensers 21 and 3|)the high-frequency potentials developed at optimum points near the endsof therespective conductors I9 and I1. Suitable operating biases for thegrid of tubesZI and 22 are produced in Well-known manner by gridrectification of the generated oscillations and appear across therespective resistors 28.and 3|, a state of sustained oscillation beingindicated by the microammeters 31 and 40. The conductors I1 and I9 thusoperate as a balanced transmission line and form a balanced resonantcircuit tunable. to the operating frequency, the latter yarying with thelengths of the conductors I 1 and I9 which extend from the partitionwall I I into the chamber I2.

Thus, the balanced resonant circuit formed by the conductors l1 and I9istunable over a range of frequencies. The dial 56, the pinion gear 54,and the rack 53 comprise means for moving the conductors I1, I8, and I9through the partition wall II to tune the resonant circuit over theoperating frequency'range. The standing waves of current developed alongthe conductors l1 and I 9 always have maximum values in the vicinity ofthe partition wall. II regardless of the lengths'of the conductors I1,I8, and I9 which extend into the chamber I2. The regions of maximummagnetic field intensity about the conductors I1 and |9, theref0re,remain stationary in the vicinity of the partition wall II throughoutthe rang of frequencies over which the balanced resonant cir-'- cuitformed by the conductors I1 and I9 is tunable. With the loop 45positioned near the conductor I9, the ultra-highfrequency signal energyin-' duced in the loop 45 and applied to the? output terminals 46, 41consequently remains maximum over the entire range of operatinfrequencies. The amplitude of the signaloutput applied to terminals 46,41 may be varied, as is well known, by adjustment of th loop 45 alongthe axis of the cylinder 43. A balanced output may be obtaine betweenthe terminals 46, 41.

The purpose of the by-pass condensers and radio-frequency choke coilsassociated with the conductors 29 and 32 and the cathode-energizingcircuit 25 is to reduce the tendency of the conductors 29, 32 and theconductors of thenergiz in circuit25 to act as parasitic resonant transmission lines, thereby to impair the operation of the oscillatorarrangement.

Fig. 3 illustrates in greater detail the construction by which thevacuum tubes 2| and-22 and their associated circuit elements are fixedlysupported on the ends of the conductors I1 and I9 to move therewith.Tube sockets 5 8,, 59-are provided for the respective vacuum tubes 2Iand 22 and are fixedly supported in spacedrelation by spacing members60, SI, 62. Two oi the sp'acing members. for example, the members 60 andBI, are fixedly securedto the ends of individual ones of the conductorsI1 and I9 by any suitable means, as soldering, welding or the like. Thethird supporting, member, for example, the member 62, is used as awinding form for the pairs of radio-frequency chokes23 and 24. Thebypass condensers 21 and 30 are conveniently formed by wrapping a ribbonof conductive material of suitable width over a layer of'li'nsulat-j ingmaterial provided near the ends of the respective conductors I9 and I1.The optimum position of these condensers varies both with thecharacteristics of the balanced resonant, circuit formed by theconductors l1 and I9 and with the constants of the vacuum-tube apparatusand circuit elements associated therewith and can best i be determinedby experiment. By-passicondensers 26, 26, Fig. 1, are convenientlyformed in similar manner on the center, conductor I8.

The region of greatest magnetic fieldintensity inthe Fig. 1 arrangementoccurs at the position occupied by the centralconductor I8 and is produced by the combinedfields of ':the conductors l1 and I9. Where themaximum possible output is desired. it is therefore necessary that theinductance piston, attenuator 43, 45 be positioned atthis point. tratedin Fig. 4 represents a modified construction by which this may beaccomplished. The arrangement of Fig. 4 is essentially sirn'ilar 'tothat of Fig. 1, similar elements being designated by similar referencenumerals, except that an additional conductor l8 permits the conductorl8 to be moved to one side of theposition which it occupies in the Fi 1arrangementwhile preserving symmetry and electrical balanceof theresonant circuit provided by the conductors I1 and I9. Symmetry andelectrical balanceis fur ther preserved by the provision of dummyracks53' and 51' on the dummy conductor I8. The

The cross-sectional view illusfierarrangement which is essentiallysimilar to the;oscillator arrangement of Fig. 1, similar elements beingdesignated'by similar reference nu morals-,except that the conductors I7and Iain the amplifier arrangement operate as unbalanced transmissionlines forming respective output and input tuned circuits of theamplifier. The central neutral conductor E8 in this arrangement islonger than in Fig. land extends through an aperture 63 in the end wallof the housing Iil. A vacuum-tube amplifier; device 84 and associatedcircuit elements therefor are enclosed Withinthe conductor I8. The'anode of tube 6-! is coupled -to the conductor I! through a condenser65, which may be formed, on the conductor IT in the manner of thecondenserfiil of Figs. 1 and 3, and is connected through radio-frequencychokeB'I and conductor 63, which extends through the tubular conductorI!. to a terminal 69 on a yoke I8, preferably of insulatingmaterial.which mechanically connects the conductors II, I8, and, I9 forsimultaneous movement through the partition wall, I I. The source ofspace current 42 is connected through a milliammeter II and a filternetwork comprising ags eries resistor. I2 and a shunt condenser It tothe terminal 69. The screen grid of tube 64 isenergized from the battery42 througha filter networkcomprisinga seriesresistor l4 and shuntcondenser I5- and .a conductor I6, which extends through thehollow-conductor I8. Additional filter networks of well-known form maybe included in the energizing circuits of the anode and screen grid ifdesired. The control electrode of. tube 54' is coupled through acondenser l1 to the end of the conductor I9 and is connected through aradio-frequency choke I8, conductor 18, a grid resistor 88, and amicroammeter 8I to the cath-v ode-energizing circuit 25.

The conductors I8 and I9 form the input resonant circuit of theamplifier and there .is consequently coupled to the conductor I 9 in aregion of its maximum magnetic field intensity, which is in the.vicinityof the. partition wall I I, an input loop or winding 82 havinginput circuit terminals 83, 84. Similar1y the conductors IT and I8 formthe output'resonant circuit of the amplifier-and there-is coupled tothis conductor I"! .an output loop or winding 85 havingoutput circuitterminals, 81, the winding 85 being; positioned in the vicinity of thepartition wall I I where there is developed the region of maximummagnetic field intensity about the conductor I'I.- I

A cross-sectional view of the apparatus of Fig. 5 is shown in Fig. 6.This view illustrates more clearly the arrangement ofa second partitionwall 88, 88 which is fixedly secured longitudinally of the housing I8 atthe elevation of the center conductor I8 and extends from the partitionwall II to the opposite end of the housing ID .to form an input circuitchamber I20. and an output circuit chamber I 2b, thus isolating theinput and output circuits of the amplifier.

The operation of the Fig.5 amplifier arrange- .men-t is'essentiallysimilar to that of the Fig.

8 oscillator arrangementexcept that. each of the conductors- I I and. ISloperats as .a resonant transmission line comprising a single-conductorunbalanced to ground as distinguished fromthe balanced pair ofconductors I I and I9 which form the tuned circuit of the Fig. Iarrangement. Input ultrae-high-frequency signalcu'rrents applied to theinput terminals 83, 84 produce along the conductor I9, when .the latteris tuned'to the frequency of the input signal by suitably proportioningthe extended length of this conductor from. the partition wall II; astanding wave of potential having maximum value near the end of theconductor. This potential is applied through the condenser TI .to thevacuum.- tube amplifier 64 where it is amplified and applied through thecondenser 85 to the output cir'-. cuit conductor 11. Since theconductors I1 and I9 are mechanically connected bythe yoke'ID and,therefore, move in unison through-the pare tition wall II, the outputcircuit conductor II istuned to the sameoperating frequency as. the

input circuit conductor I9. Consequently, there is developed along theconductor I! a standing wave of current having maximum value in theregion. of the partition wall I I, and, therefore, in proximity to theoutput loop or winding85. The maximum value of amplified high-frequencysignalcurrent is thus induced in the loop 85 and applied'to the outputterminals, 81. The meter BI, in this operation, provides an indicationof the input-signal level at the control grid oftubefi L I g 7 While theamplifier construction of Figs. 5. and

. 6 is of the unbalanced or single-ended type, a

push-pull or balanced amplifier may be provided using the balancedconstruction disclosed in the oscillator arrangement of Figs. 1 and 2.Alsosev eral stages can be cascaded by-connecting the output terminals86; 87 of one stage to the input terminals 83, 84 of the next stage. IFrom the above description of the invention, it will be evident that anultra-high-frequency signal-translatingapparatus embodying the inventionhas the advantage that the region of maximum magnetic field'intensity ofits tuned inputand output circuits remains stationary at a predeterminedfixed location over a wide range. of tuning frequencies, thus ensuringthat the transfer of signal energy to and from the apparatus by fixedinductive coupling means remains maximum over a wide range offrequencies over which the apparatus is adapted to operate. Theinvention has the additional advantage, where the apparatus includes atleast two tuned circuits of the resonant transmission line type, that.

both circuits are simultaneously andaccurate'ly tuned to the sameoperatingfrequency, thus greatly simplifying the adjustment of theapparatus for operation over theoperating frequency range. 1 While therehave been described what are at I present considered to be the preferredembodi- 7Q porting said conductor, means including said conments of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be madev therein without departingfromtheinvention, and it is, therefore, aimed in the appended claims tocover all such changes,

and modifications as fall within the true spirit and scope of theinvention.

. What is claimed is:

1. An ultra-high-frequency signal-translating" apparatus comprising, anelongated rigid conductor, a fixed conductive member slidably sup- '9'?ductor for forming a resonant circuit tunable over a range offrequencies by adjustment of the length of said conductor extending fromone side of said member, means movable in unison with said conductor forsupporting vacuum-tube apparatus and associated circuit elements at theend of said conductor on said one side of said member, and means formoving said conductor through said member to tune said resonant circuitto a predetermined operating frequency in said frequency range.

2. An ultra-high-frequency signal-translating apparatus comprising, anelongated rigid conductor, a fixed conductive member having an aperturein which said conductor is slidably supported, means including saidmember for completing an electrical ground connectionto said conductorsubstantially at the point of support thereof by said member, meansincluding said conductor for forming a resonant circuit tunable over arange of frequencies by adjustment of the length of said conductorextending from one side of said member, means movable in unison withsaid conductor for supporting vacuum-tube apparatus and associatedcircuit elements at the end of said conductor on said one side of saidmember, and means for moving said conductor through said member to tunesaid resonant circuit to a predetermined operating frequency in saidfrequency range.

3. An ultra-high-frequency signal-translating apparatus comprising, anelongated rigid conductor, a fixed conductive member slidably supportingsaid conductor, means including said conductor for forming a resonantcircuit tunable overa range of frequencies by adjustment of the lengthof said conductor extending from one side of said member, means forsupporting vacuum-tube apparatus and associated circuit elements on thatend of said conductor which is on said one side of said member, andmeans for moving said conductor through said member to tune, saidresonant circuit to a predetermined operating frequency in saidfrequency range.

4. An ultra-high-frequency signal-translating apparatus comprising, anelongated rigid conductor, a fixed member slidably supporting saidconductor and providing an electrical connection thereto, meansincluding said conductor for forming a resonant circuit tunable over arange of'frequencies in accordance with the length of said conductorextending from one side of said member, the region of maximum magneticfield intensity about said conductor remaining stationary in thevicinity of said one side of said member over said range of frequencies,means for moving said conductor through said member to tune saidresonant circuit to a predetermined operating frequency in saidfrequency range, and an output circuit including a loop disposed in saidregion of maximum magnetic field intensity.

5. An ultra-high-frequency signal-translating apparatus comprising, anelongated metallic housing, a conductive apertured partition disposedtransversely within said housing to divide the interior thereof into twochambers, an elongated rigid conductor, means for slidably supportingsaid conductor in an aperture of said partition and for making anelectrical connection between said conductor and said partition at afixed point near said partition, means including said conductor forforming a resonant circuit tunable over a range of frequencies byadjustment of the length of said conductor extending from one side ofsaid partition, the region of maximum magnetic field intensity aboutsaid conductor remaining stationary in the vicinity of said one side ofsaid partition over said range of frequencies, means for moving saidconductor through said partition to time said resonant circuit to apredetermined operating frequency in said frequency, range, and anoutput circuit including a loop disposed in said region of maximummagnetic fi'eld intensity.

6. An ultra-high-frequency signal-translating apparatus comprising, apair of elongated rigid conductors, a fixed member slidably supportingsaid conductorsiin parallel spaced relation and providing an electricalconnection therebetween, said conductors forming at least one resonantcircuit tunable over a range of frequencies by adjustment of the lengthsof said conductors extending from one side of said member, means movablein unison with said conductors for supporting vacuum-tube apparatus andassociated circuit elements at the end of said conductors on said oneside of said member, and means for moving said conductors inunisonthrough said member to tune said resonant circuit to a predeterminedoperating frequency in said frequency range.

7. An ultra-high-frequency signal-translating apparatus comprising, apair of elongated rigid conductors, means including a fixed member forslidably supporting said conductors in parallel spaced relation and forcompleting an electrical connection between said conductorssubstantially at the point of support thereof, said. conductors formingat least one resonant circuit tunable over a range or frequencies byadjustment of the lengths of said conductors extending from one side ofsaid memberymeans movable in unison with said conductors for supportingvacuumtube apparatus and associated circuitelements at the end of saidconductors on said one side of said member, and means for moving saidconductors in unison through said member to tune said resonant circuitto a predetermined operating frequency in said frequency range.

8. An ultra-high-frequency signal-translating apparatus comprising,three elongated rigid conductors, a fixed member slidably supportingsaid conductors in parallel spaced relation and providing an electricalconnection therebetween, said conductors forming two, resonant circuitshaving one conductor common to each and tunable over arange offrequencies by adjustment of the lengths of the other two of saidconductors extending from one side of said member, means movable inunison with said conductors for supporting vacuum-tube apparatus andassociated circuit elements at the end of said other two conductors onsaid one side of said member, and means formoving said conductors inunison through said member simultaneously to tune both of said resonantcircuits over the same frequency range.

9. An ultra-high-frequency signal-translating apparatus comprising,three elongated rigid conductors, a fixed member slidably supportingsaid conductors in parallel spaced relation and providing an electricalconnection therebetween, said conductors forming two resonant circuitshaving one conductor common to each and tunable over a range offrequencies by adjustment of the lengths of the other two of saidconductors extending from one side of said member, each of said othertwo of said conductors having a maximum magnetic field intensitythereabout which remains stationary in the vicinity of said one side ofsaid member over said range of frequencies, means for moving saidconductors in unison through said member simultaneously to tune both ofsaid resonant circuits over the same frequency range, and input andoutput circuits'including input and output loopsdisposed in individualones of said regions of maximum magnetic field intensity.

. 1'0. An ultra-high-frequency signal-translating apparatus comprising,an elongated rigid tubular conductor, a fixed member slidably supportingsaid conductor and providing an electrical connection thereto; meansincluding said conductor for forming a resonant circuit tunable over arange of frequencies by adjustment of the length of said conductorextendingfrom one side of. said member, means for fixedly supportingvacuum-tube apparatus and associated circuit elements on that end ofsaid conductor which is onisaid one side of said member, an electric.circuityextending through said conductor and electrically insulatedtherefrom for energizing said vacuum-tube apparatus, and means formoving said: conductor through said member to. tune said resonantcircuit to a predetermined operating frequency in said frequency range.

11. An ultra-high-frequency signal-translating apparatus comprising, anelongated metallic housing, a conductive apertured partition disposedtransversely Within said housing to. divide the interiorthereof into twochambersia plurality of elongated rigid tubular conductors, means forslidibly supporting said conductors in individual apertures of saidpartition and for making an 'electricalconnection between saidconductors and said: partition at a fixed point near said partition,means including said conductors for forming at least one' resonantcircuit tunable over a range of frequencies by adjustment of the lengthsof 7 said, conductors extending from one side of said partition, theregion of maximum magnetic field intensity about said conductorsremaining stationary in the vicinity of said one side of said partitionover said range of, frequencies, means for moving said conductorsthrough said partition to tune said resonant circuit to a predeterminedoperating frequency in 1 said frequency range, means movable in, unisonwith said conductors for supporting vacuum-tube apparatus and associatedcircuit elements in one-of said chamberls, currentpsupply means in theother of said chambers, current supply leads'extending througlii tween,said conductors forming at least one resonant circuit tunable overa'range'of irequencies by adjustment of the lengths of said conductorsextending from one side of saidmem ber and the region of maximummagnetic field" intensity about said conductors" remaining 1 Sta tionaryin the vicinity of said one side of said member over said range offrequencies, means' for moving said conductors in unison througli'sai'clmember to tune said resonant circuit to a pr determinedoperating frequency in said frequency range, and an output-circuitincluding a loop disposed in said region I of maximummagnetic fieldintensity. 7

13. An ultrahigh-frequency-signal-translat-' ing apparatus comprising,anelongated rigid cbn :v ductor, a fixed conductive member slidablysup-iporting said conductor, means including said eon ductor for forming aresonant circuit tunable over a range of-frequencies by adiustmentofthelength of said conductor extending from one side of said member, theregion of maximum magnetic field'- intensity' about saidconductorremaining stationary in the vicinity of said one side of said member"over said range of frequencies, means for moving said conductor throughsaid member to tune said resonant circuit to a predetermined operatingirequency in said frequency range, and an inductance typeof pistonattenuator fixedly positioned with respect to said conductive member andin'-'-- eludinga loop movable intoand out of said region of maximumfie1dintensity,-. i

14. In an ultra-high-frequency' signal trans latingv apparatus, a pushpul-l oscillator com-prising, a, plurality of elongated rigidconductors; a fixed conductive member slidably siipporting saidconductors, means including-said conductors for forming at leastoneresonant circuit-tunable over a range of frequencies by adjustment ofthelengths of said conductors extending from one side of said member,the region of maximum magnetic field intensity aboutsaid conductorsremaining stationary inthe vicinity of said one. side of saidmember oversaid range of frequencies, means. for moving said, conductors throughsaid member to tune said resonant circuit to a predator. mined,operating frequency in said frequency range, means movable in unison,with said conductors for supporting a pair of vacuum tubes andassociated circuit elements at the end of said (1011- v ductors onsaid.- one side. of saidmember, means for connecting thev outputelectrodes. of said vacuum tubesto individual ones ofjsaid conductors.

lator, and an output circuit including a loop disposed inthe region ofmaximum magnetic field intensity of at least one of said conductors.

RICHARD B. LAWRANTCE; o

